JPH0134634B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a cloth feeding device for a sewing machine.

[Prior Art] In a conventional sewing machine, the cloth to be sewn is fed by a feed dog. It is configured to feed the cloth intermittently between the two.

These feed dogs are actuated by a drive mechanism,
This drive mechanism and the feed dog constitute a cloth feed device of the sewing machine.

This fabric feeding device feeds the fabric accurately, controls the amount of fabric fed, allows the sewing machine to sew accurately, and adjusts the stitch length and thread tension. The fabric feeding device is an important part of a sewing machine.

For this reason, various cloth feeding devices have been developed to date, such as the one disclosed in Italian Patent No. 856128 filed by the same applicant as the present applicant.

Some industrial sewing machine feed devices are equipped with two sets of feed teeth. This includes a main feed dog and a differential feed dog, which are operated synchronously with each other.

The above-mentioned main feed dog is called a stitch feed dog, and controls the feed amount of the fabric that is fed below the presser leg of the needle.

In addition, the feed amount of the differential feed dog is larger than the feed amount of the main feed dog, which causes wrinkles or sagging of the cloth, and the feed amount of the differential feed dog is Give tension to the fabric by making it smaller than the amount.

The slack of the cloth mentioned above is given according to the elasticity of the cloth, and the tension of the cloth is given when the cloth to be sewn is an elastic cloth, and the elasticity of the cloth prevents the sewing operation. To prevent. However, when sewing this fabric with tension applied to it, when the fabric is sewn under tension and is released from the tension after sewing, it contracts, causing the sewing thread to become excessively long and causing the stitches to loosen. There is.

For this reason, the differential feed dog is configured to be able to adjust the difference between its cloth feed amount and the cloth feed amount of the main feed dog, and to be synchronized with the main feed dog.
Therefore, this drive mechanism includes three drive shafts driven by one main shaft, and has a complicated movement mechanism. Vertical synchronization of these feed dogs is achieved by a cam installed on the rotating shaft.
Horizontal synchronization is also provided by a connecting rod/crank mechanism. These conventional synchronization mechanisms have complicated structures made up of many parts and are prone to failures. Further, in these devices, it is troublesome to adjust the feed amount of the differential feed dog with respect to the feed amount of the main feed dog. Therefore, in a sewing machine equipped with two sets of feed dogs, the fabric feed device is complicated, its adjustment is troublesome, the cost is high, and the reliability is insufficient.

[Problems to be solved by the invention] The present invention has been made based on the above circumstances, solves the above-mentioned problems, has a simple structure,
To provide a cloth feeding device which has a small number of parts and can be easily adjusted even by an unskilled user. A particularly important object of the invention is to allow for both large and precise adjustment of the differential feed dog relative to the main feed dog.

Another important object of the present invention is to reduce the size of this cloth feeding device so that it can be easily incorporated into a sewing machine.

[Means for Solving the Problems and Their Effects] In order to achieve the above object, the cloth feeding device of the present invention includes one set of main feeding teeth and one set of differential feeding teeth. They are configured to operate synchronously and feed the fabric on the needle plate. and,
These feed dogs are vertically supported by two support elements, a first and a second support element, so as to be able to freely vibrate, and these support elements are connected to a rotatable main shaft and a second shaft disposed along the main shaft. It is driven by an eccentric member provided. Also,
These feed dogs are driven horizontally and synchronously by a stirrup-like member supported on the second shaft by the first and second sleeves. This second
The shaft is divided into first and second shaft halves.

The first shaft half of the second shaft is connected to the main shaft via an adjustment eccentric mechanism, and is reciprocated in synchronization with the main shaft. Further, the second shaft half is continuously rotated in synchronization with the main shaft. Further, the main feed dog is attached to the first support element, and the differential feed dog is attached to the second support element. These support elements are supported by elevating cams provided on the second shaft halves of the main shaft and the second shaft, and blocks fitted thereto, so that the main shaft and the second shaft halves rotate. This causes the first and second support elements to move up and down synchronously, and the main feed dog and the differential feed dog to move up and down synchronously by the same amount. Further, a generally U-shaped stirrup-like member having two arm portions is provided, and this stirrup-like member reciprocates integrally with the second shaft half of the second shaft. An elongated cutout groove is formed in the arm portion of this stirrup-like member, and an adjusting sliding member is attached to these grooves so that the position thereof can be freely adjusted. Further, grooves are formed in the support element, and the adjustment sliding members are fitted into these grooves, and the support elements are adjusted in the horizontal direction, that is, in the cloth feeding direction, through these adjustment sliding members. Rotated back and forth.
By changing the mounting positions of these adjusting sliding members, the distance from the center of reciprocating rotation of this stirrup-like member to these sliding members, that is, the arm length, is changed, and the first and second support elements are adjusted. The amount of reciprocating movement in the horizontal direction, that is, the amount of feed of the main feed dog and the differential feed dog can be adjusted separately.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In the figure, the entire fabric feeding device of the present invention is designated by the reference numeral 1.

The sewing machine 2 is equipped with a base 3, a column 4, an arm 5, and a head 6 as in the conventional sewing machine.

A main shaft 7 is provided through the base 3, and a pulley 8 and a handwheel 9 are attached to a protrusion of the main shaft. and,
This pulley 8 is configured to be driven by a motor via a drive belt as in the conventional case.

The main shaft 7 drives an upper shaft 11 via a belt 10 and a pulley, and operates a needle 13 via a conventional link mechanism 12.

This needle 13 is placed close to the presser foot 14,
This presser foot 14 is arranged above the needle plate 15, and this needle plate is also provided with a feed dog for feeding the cloth. This feed dog
As shown in the figure, it is composed of one set of main feed dog 16 and one set of operating feed dog 17, and this operating feed dog 17 is arranged on the rear side in the cloth feeding direction with respect to the above main feed dog 16. has been done.

The main shaft 7 is provided through the entire length of the base 3 and through a cover 18 provided on the opposite side to the handwheel 9.
The above-mentioned feed dogs 16, 17 are operated by.

Further, the main shaft 7 is configured to drive other mechanisms of the sewing machine, but since these other mechanisms are not related to the present invention, illustration thereof is omitted.

However, to illustrate another mechanism, reference numeral 19 in FIG. 1 is a hook drive mechanism, which moves the hook of the sewing machine 2 back and forth in the axial direction of the sewing machine, and threads each stitch. Hook and release again.

Further, the feeding device of the present invention has the above-mentioned main shaft 7 and the second
The shaft 20 is driven by two shafts. This second shaft 20 is divided into two shaft halves as shown in FIG. The first shaft half 21 and the second shaft half 22 are arranged coaxially with each other and are rotatably engaged with each other. These two shaft halves 21 and 22 are rotatably supported separately from each other, and a driving member is attached to each tip end thereof.

The first shaft half 21 is connected to a connecting rod 24 via a swing arm 23, and is further connected to an eccentric mechanism 25 for stitch adjustment provided on the main shaft 7. The structure of this eccentric mechanism 25 for seam adjustment is similar to that of the conventional one, and its structure is disclosed, for example, in Italian Patent No. 951304 filed by the same applicant as the present applicant.

Further, the tip of the second shaft half 22 is connected to the end of the main shaft 7 via a toothed belt 37 and pulleys 37a, 37b. This coupling mechanism is disposed within the left side portion of the base 3 and is configured to facilitate maintenance.

Further, the second shaft half 22 of this second shaft is arranged parallel to the above-mentioned main shaft 7 and configured to rotate together with this main shaft 7, and the first shaft half of this second shaft The half portion 21 is configured to reciprocate in response to the rotation of the main shaft 7 described above.

Further, the second shaft half 22 of the second shaft 20 described above
Two support elements are provided above the main shaft 7. The first support element 26 is connected to the main feed dog 16 via a connection member, and the second support element 27 is connected to the differential feed dog 17 via another connection member.

These support elements 26, 27 are shown in FIGS. 4 and 5. Each of these support elements has a flat plate shape, and a first fork 28 and a second fork 29 are formed at both ends thereof, respectively. This is fork 28, 29
are oriented in directions opposite to each other, and mechanisms for raising and lowering these support elements 26, 27 and the feed teeth 16, 17 are provided in these forks, respectively.

These elevating mechanisms have the same structure and are composed of an elevating eccentric member 30, such as an eccentric force, and a block 31, which surrounds the elevating eccentric member 30 and is slidably fitted into the forks 28, 29. It matches.

Then, the first fork 28 is connected to the second fork 28.
The second fork 2 is connected to the shaft 20 of the
9 is connected to the main shaft 7. One eccentric member 30 is provided on each of the second shaft and the main shaft, and each fork of each support element 26, 27 is fitted into a corresponding block 31, respectively.

Further, as shown in the figure, vertical grooves 32 are formed in the support elements 26 and 27, and first and second protrusions are formed in the first support element 26 and the second support element 27. 33 and 34 are provided in a protruding manner, and a first connecting member 35 and a second connecting member 36 are connected to these convex portions, respectively. and,
These connecting members 35 and 36 support the main feed dog 16 and the differential feed dog 17, respectively, as shown in FIG. 2 via other convex portions.

These connecting members 35 and 36 are connected to the above-mentioned convex parts 33 and 34 by screws, and these screws are screwed into holes formed in the above-mentioned convex parts. An eyelet is formed for insertion.

Further, the above-mentioned holes are arranged at the positions of the respective vertices of the equilateral triangle, and screws are threaded into each of these holes, and the positions of the above-mentioned connecting members 35 and 36 are determined by the amount of protrusion of these screws. , and the positions of the feed dogs 16 and 17 are determined. By arranging these holes at the vertices of the equilateral triangle, the feed teeth 16 and 17 can be accurately aligned with the plane of the needle plate 15.

Further, a stirrup-like member 38 is provided on the second shaft 20. This stirrup-like member has an inverted U-shape and has two sleeves arranged coaxially with each other. The first sleeve 39 is fixed to the first shaft half 21 by a screw, and the second sleeve 40 is rotatably supported by the second shaft half 22.

Further, both legs or arms of this stirrup-like member 38 are arranged along opposite sides of the first and second support elements 26, 27. Each of the arm portions is formed with an elongated notch groove 41 extending substantially vertically. In addition, the support elements 26, 2
Approximately vertical grooves 32 corresponding to these notched grooves 41 are formed on the side surfaces of each of the grooves 7 . Then, the adjustment sliding member 4 passes through the notch groove 41.
2 are provided respectively, and these sliding members 4
2 can be freely moved along this notched groove 41 by loosening a nut 43, and can be fixed at any position in this notched groove 41 by tightening this nut 43. These sliding members 42 are slidably fitted into the grooves 32 of the support elements 26, 27. The lengths, positions, etc. of these notched grooves 41 and grooves 32 are set in accordance with the necessary feed amount and adjustment range of the feed amount of the main feed dog 16 and the differential feed dog 17.

Next, the operation of the above-described feeding device will be explained.
When the main shaft 7 is rotated, the second shaft half 22 of the second shaft 20 is coupled and rotated in synchronization with the rotation. Accordingly, the lifting eccentric member 30 rotates, and the first and second support elements 26, 27 move up and down together in the vertical direction via the block 31. Therefore, the main feed dog 16 and differential feed dog 17 attached to these also move up and down together. In this case, the stirrup-like member 38 does not move up and down in a reciprocating manner, but the sliding member 42 slides within the grooves 32 of the support elements 26 and 27, so that the support elements move up and down. Permissible.

On the other hand, the first shaft half 21 of the second shaft 20 described above
is reciprocated in synchronization with the main shaft 7 by an eccentric mechanism 25. This first shaft half 21
At the same time, the stirrup-like member 38 also rotates back and forth.
By this reciprocating rotation of the stirrup-like member 38, the first and second support elements 26, 27 are reciprocated in the horizontal direction via the sliding member 42.
The amount of horizontal movement of these support elements 26, 27 corresponds to the distance from the corresponding sliding member 42 to the center of rotation of the stirrup-like member 38, that is, the arm length. Therefore, by adjusting the positions of these sliding members 42, the horizontal movement amount of these support elements 26, 27, that is, the horizontal feed amount of the main feed dog 16 and the differential feed dog 17 can be adjusted separately. can do.

Furthermore, the device of the present invention has a simple structure, is small, and has a small number of parts. In addition, this allows easy adjustment of the stroke of the main feed dog 16 and the differential feed dog 17, and furthermore, the adjustment range of this stroke can be widened.

Note that the details of this embodiment may be changed to other configurations.

Further, the material, shape, dimensions, etc. can be changed as appropriate.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which Figure 1 is a vertical sectional view of the entire sewing machine, Figure 2 is a perspective view of the feed mechanism, and Figure 3 is a perspective view of the feed mechanism.
The figure is a partially sectional front view of the feeding mechanism shown in FIG. 2, FIGS. 4 and 5 are side views and front views of the support element shown in FIGS. 2 and 3,
Figures 6a and 6b are views of the connecting members shown in Figures 4 and 5, viewed from directions orthogonal to each other;
FIGS. 7a and 7b are views of the second connecting member shown in FIGS. 4 and 5, viewed from directions orthogonal to each other. 1...Feeding device, 2...Sewing machine, 7...Main shaft,
15... Needle plate, 16... Main feed dog,
17... Differential feed dog, 20... Second shaft, 21...
...first shaft half, 22...second shaft half, 26,
27... Support element, 28, 29... Fork, 35... First connecting member, 36... Second
connecting member, 42...sliding member.

Claims (1)

[Claims] 1. A device for feeding cloth in a sewing machine, comprising: a. A rotatable main shaft 7; b. A second shaft 20 disposed near and parallel to the main shaft 7; This second shaft is composed of first and second shaft halves 21 and 22, and these shaft halves are arranged coaxially with each other and are rotatable independently of each other; A stitch adjustment eccentric mechanism 25 is provided, and this mechanism is connected to the first shaft half of the second shaft and rotates it back and forth, and adjusts the stitch length according to the desired stitch length. The amount of reciprocating rotation of the first shaft half can be adjusted; The main feed dog and the differential feed dog 16, 17 are provided with means 37, 37a, 37b for rotating;
support elements 26 each holding a
27, and each of these support elements has two blocks 3 engaged with a lifting cam 30.
1, one of these blocks is fitted into a lifting cam integrally provided on the main shaft 7, and the other block is supported by the second shaft of the second shaft. 2 shaft half 2
2, for raising and lowering the support elements in synchronization with each other; 39 is formed and the first sleeve is integrally attached to the first shaft half 21 of the second shaft, and the other end of the stirrup-like member has a second sleeve.
A sleeve 40 is formed, and this second sleeve is rotatably supported on the second shaft half 22 of the second shaft; are attached to the substantially U-shaped stirrup member 38 by passing through cutout grooves 41 formed in both arm portions thereof, and these sliding members are mounted on the support elements 26 and 27 in the vicinity of the cutout grooves 41. and are slidably fitted into grooves 32 formed corresponding to these, respectively, and
Via these sliding members 42, the reciprocating rotation of the first shaft half 21 of the second shaft and the stirrup member is controlled by the respective support elements 26,
27, said first shaft half and said second shaft half.
By adjusting the distance from the axis of the second shaft 20, which is the common axis of the shaft halves 21, 22, to these adjusting sliding members 42, the horizontal direction of each of the support elements 26, 27 can be adjusted. A cloth feeding device for a sewing machine, which is characterized by adjusting the amount of reciprocating operation. 2. The sewing machine according to claim 1, wherein the support elements 26 and 27 are fitted into the block 31 via fork portions 28 and 29 oriented in opposite directions. Cloth feeding device. 3. The first shaft half 21 of the second shaft 20 is connected to the second shaft half 2 at the center of the second shaft.
2. A cloth feeding device for a sewing machine according to claim 1, wherein the cloth feeding device is rotatably fitted into a cloth feeding device of a sewing machine. 4. The substantially U-shaped stirrup member 38 has two arm portions, which are integrally formed with the first and second sleeves 39, 40, and which are integrally formed with the first and second sleeves 39, 40. 2. The fabric feeding device for a sewing machine according to claim 1, wherein the fabric feeding device is arranged along opposite surfaces of the support elements (26, 27). 5. The support elements 26, 27 are connected to the main feed dog and the differential feed dog via connecting members 35, 36 which are adjustable with respect to these support elements. A cloth feeding device for a sewing machine according to claim 1.